1. Technical Field:
The invention relates to apparatus for the connection of optical and electrical devices and more particularly to an attachment mechanism for use between an electronic circuit board and optical cable.
2. Description of the Related Art:
An optical link card for an electronic data processing system must provide for conversion between parallel electronic data and serial optical data in two directions. A serializer converts the data to be transmitted from a parallel format to a serial format. Then a laser in an optical subassembly converts the serial electrical pulses to optical pulses. Data received over an optical link is convened to electrical pulses and then applied to a deserializer to place it in parallel format. The complication caused by conversion of the data between electrical and optical formats is more than offset by the boost in data transmission capability afforded by use of high speed optical data transmission channels.
Optical link cards should exhibit a high degree of standardization and be readily incorporated into a number of platforms, particularly personal computers or workstations. As may be expected, a number of problems can occur when this is done. Packaging electrical and optical components together exposes the optical devices to the heat output of the electrical devices. Optical components such as lasers are highly heat sensitive. Placement of the card in a workstation can reduce airflow around the card impeding cooling. Mechanical strain may be placed on pins of the circuit board where it connects to a motherboard within the computer. Also, most circuit boards used for connection to external cables use edge mounted connections to the circuit board. However, edge mounting is not a practical arrangement for optical subassemblies.
Additionally, the high speed data rates make impedance matching between electronic circuitry and the optical subassemblies an important consideration.